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Serum Creatinine (Creatinine Level)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of creatinine, a waste product from muscle metabolism, in your blood. It helps assess how well your kidneys are filtering blood.

Quick summary

["Your kidneys filter waste from your blood, and creatinine is a key marker of kidney function."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
73517-5
Short code
Atenolol ind plt IgM SerPl Ql FC
Synonyms
Atenolol ind plt IgM SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

Creatinine levels help doctors check for kidney problems. High levels may indicate reduced kidney function or kidney disease, while low levels could suggest overhydration or muscle loss.

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm. If you’re on a low-protein diet or have had recent muscle activity, let your doctor know.

Possible Results and Their Implications

Results are compared to a general reference range, but individual results can vary based on age, sex, muscle mass, and hydration status. Consistently high levels may signal kidney issues, while persistently low levels might warrant further evaluation.

Common Causes of Abnormal Results

High creatinine levels can result from kidney disease, dehydration, severe muscle injury, or conditions like diabetes or heart failure. Low levels may occur with overhydration, liver disease, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Creatinine

Frequently asked questions

How often should I get this test?
Your doctor may recommend this test periodically if you have kidney-related conditions, high blood pressure, diabetes, or a family history of kidney disease. Regular monitoring helps track kidney function over time.
Can diet affect creatinine levels?
Yes, diet can influence creatinine levels. High-protein diets may temporarily increase levels, while dehydration can raise them. Hydration and muscle mass also play a role.
What should I do if my creatinine level is high?
If your creatinine level is elevated, your doctor may recommend lifestyle changes (like staying hydrated), adjusting medications, or further testing to identify the cause and manage kidney health.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy